This pre-doctoral research support application is structured to prepare the applicant to compete for a research-oriented faculty position in psychiatric and genetic epidemiology. Specifically, training & supervised research experience will focus on combining epidemiologic, statistic, & behavior genetic methods to study the etiology of child psychiatric disorder co-occurrence. Disorder clustering, severity, shared genetic influence, & outcomes will be examined to assess the relationship of comorbid psychopathology with Attention Deficit Hyperactivity Disorder (ADHD). ADHD is a multi-dimensional disorder characterized by symptoms of hyperactivity, impulsivity, & inattention, thus, externalizing & internalizing disorders may co-occur differentially. Genes or the environment both likely influence the etiology of these disorders & their permutations in different ways. This pre-doctoral fellowship award will allow the applicant to: 1) conduct secondary data analysis of two existing datasets to systematically examine comorbidity with ADHD & influences on disorder clustering employing contemporary statistical methodology & 2) complete coursework & training in these methods, psychiatric epidemiology, & gain an introduction to molecular genetics. [unreadable] [unreadable] [unreadable]